ARHGAP18 and Parkinson disease: Several of the human stable genes (or related family members), e.g., GSG1L, ATP2A3, SLC17A6, SLIT1,RGS16, KCNIP1, CDH13, TCF12, OSBPL1A, OSBPL10, GNG7, ARHGAP18, ARHGAP24, PCSK5, PEG3, HLA-DOA, HLA-DRA, HLA-DRB1, and PDE8B are dysregulated in PD (Cantuti-Castelvetri et al., 2007; Bossers et al., 2009; Simunovic et al., 2009) and/or are represented in PD datasets from genome wide association studies2 (GWASdb SNP-Disease Associations dataset).